Table 3.

Association of percentage density with breast cancer recurrence and survival

	Model 1a			Model 2b
	HRc	95% CI	P value	HRc	95% CI	P value
Local recurrence 62 events Total time at risk = 9,683 years	1.99	1.09-3.66	0.026	1.92	1.03-3.57	0.039
Locoregional recurrence 103 events Total time at risk = 9,606 years	1.84	1.16-2.91	0.010	1.67	1.04-2.69	0.033
Distant recurrence 181 events Total time at risk = 9,618 years	1.28	0.90-1.82	0.170	1.08	0.74-1.56	0.698
5-year breast cancer-specific survival 124 events Total time at risk = 8,489 years	1.25	0.82-1.92	0.299	0.97	0.61-1.54	0.908
10-year breast cancer-specific survival 213 events Total time at risk = 16,016 years	1.34	0.97-1.85	0.080	1.08	0.77-1.53	0.644
Overall 5-year survival 174 events Total time at risk = 8,489 years	1.07	0.73-1.55	0.742	0.89	0.60-1.32	0.554
Overall 10-year survival 358 events Total time at risk = 16,016 years	1.14	0.87-1.48	0.343	0.99	0.75-1.29	0.921

^aAdjusted for age, body mass index (BMI), and hormone replacement therapy (HRT) use;

^badjusted for age, BMI, HRT use, mode of detection, tumor size, lymph node metastasis, estrogen receptor status, progesterone receptor status, and grade;

^chazard ratio (HR) comparing percentage density (PD) ≥25% to PD <25%. CI, confidence interval.